Lack of association between a serotonin transporter promoter polymorphism and BP1 in Antioquia, Colombia

We have examined the frequency of a functional length polymorphism in the promoter region of the serotonin transporter (5-HTTLPR) in a case/control sample for bipolar mood disorder type 1. Patients (N=98) and controls (N= 104) were collected from the isolated population of Antioquia, Colombia. Cases were evaluated using the Diagnostic Interview for Genetic Studies (NIMH). Normal controls were randomly selected individuals matched with cases for sex and over 35 years old. Genomic DNA samples were genotyped using the experimental conditions reported by Lesch et al. (Science 274, 1527-1531). Allele frequencies for the cases were 1 = 0.52 s = 0.48 and for the controls 1 = 0.47 s = 0.53 . Genotype frequencies for the cases were 1/1= 0.29 1/s= 0.45 s/ s= 0.26 and for the controls: 1/1= 0.19 1/s= 0.56 s/s= 0.25. No statistically significant deviation from Hardy Weinberg expectation was detected in the two groups. No statistically significant difference in the allele (chi square 0.47, p=0.493) or genotype (chi square 3.08, p=0.214) frequencies was observed between cases and controls. Thus we detected no evidence of association of this polymorphism with bipolar disorder in this sample.